One of Untapped Cities’ exclusive tours is a visit inside the normally off-limits Bialystoker Synagogue on the Lower East Side. This landmarked building, which was built in 1826, encapsulates what we love about New York City – many layers of history, quirky details, and hidden places within a building you might just walk by and never notice.

Below, here are some of the secrets of the building you’ll learn on our tour, which also includes a walk to other historic sites along East Broadway. Get tickets for the tour here:

10. Bialystoker Wasn’t Built As a Synagogue

As you might guess from the Federal-style architecture of the Bialystoker Synagogue, it was not built as a Jewish house of worship. In fact, it was originally the Willet Street Episcopal Church, a congregation that served the new community rising on the former estate and orchards of James de Lancey, Jr., a Loyalist who lost his property holdings after the American Revolution. The Willet Street Episcopal Church was built in 1826, but changing demographics on the Lower East Side led to a steady decline in congregation size starting in the 1880s.

In 1905, the congregation Chevra Anshei Chesed of Bialystok, which was formed on the Lower East Side by Polish immigrants from the town of Bialystok in 1865, purchased the building for use as a synagogue.